Didcomm message exchange backend in service layer structure

[hugoib]

Implement this logic: https://github.com/ADORSYS-GIS/wallet-vc-libs/blob/main/docs/service-layer/other-events.md#retrieve-messages

[IngridPuppet]

I'm not sure where the pickup protocol will come into play, but it will. Here is the link to the spec: https://didcomm.org/messagepickup/3.0/.

[Ogenbertrand]

Working on this.

[hugoib]

The difference between this ticket and #55

Is that this ticket will handle the BE part interaction with the mediator. Yes, the message pickup:

https://github.com/ADORSYS-GIS/wallet-vc-libs/tree/main/docs/service-layer#alice-checks-status-requests

Ticket 55 handles the communication between FE and BE. Once the messages are already inside the DB of the BE. Since we are implementing a polling structure, it has different calls.

[hugoib]

Currently troubleshooting an error in which a did:peer is generated twice during the mediation coordination. After this wrongly double generation, the wrong one is stored on the storage.

This needs to be fixed in order to make the next needed calls.

[IngridPuppet]

Currently troubleshooting an error in which a did:peer is generated twice during the mediation coordination. After this wrongly double generation, the wrong one is stored on the storage.

I would not say the double generation is wrong, just that both aren't stored; unless you also plan to separate the keylist update step. Compare with RootsID's notebook for Alice:

alice_did_for_mediator = await create_peer_did(1,1)
...
alice_did_for_bob = await create_peer_did(1, 1, service_endpoint=[{"uri": mediator_routing_key}])

[hugoib]

This issue is originally composed of 3 calls:

1. https://didcomm.org/messagepickup/3.0/status-request
2. https://didcomm.org/messagepickup/3.0/delivery-request
3. https://didcomm.org/messagepickup/3.0/messages-received

Call 1 and 2 are working on the playground of this commit:

76ada06

Next step, cleanups, add event layer and add tests.